The present invention relates to a sensing device having a bridge circuit.
A sensing device having a bridge circuit is commonly used as a sensor to measure a target condition (such as a pressure, a load, a vibration, a temperature or a flow rate) in response to resistance changes in the bridge circuit.
The present invention is to provide a sensing device with a bridge circuit, which can detect a target condition stably while monitoring an anomaly in the sensing device, such as a break in circuit wiring, to secure a high degree of reliability.
According to an aspect of the present invention, there is provided a sensing device, comprising: a first resistive branch comprising first and second resistors connected in series; a second resistive branch comprising third and fourth resistors connected in series, the second resistive branch being arranged in parallel with the first resistive branch to form a bridge circuit for measurement of a target condition; a first feed wiring arrangement connecting the first resistive branch to a power source side; a second feed wiring arrangement connecting the second resistive branch to the power source side in parallel to the first feed wiring arrangement; and a ground wiring arrangement connecting the first and second resistive branches to a ground side.
According to another aspect of the present invention, there is provided a sensing device, comprising: a first resistive branch comprising first and second resistors connected in series; a second resistive branch comprising third and fourth resistors connected in series, the second resistive branch being arranged in parallel with the first resistive branch to form a bridge circuit for measurement of a target condition; a first wiring arrangement connecting the first and second resistive branches to a first side, the first side being one of a power source side and a ground side; and a second wiring arrangement connecting the first and second resistive branches to a second side, the second side being the other of the power source side and the ground side, wherein the first wiring arrangement comprises a first wire connecting the first resistive branch to the first side and a second wire connecting the second resistive branch to the first side in parallel to the first wire.
According to still another aspect of the present invention, there is provided a sensing device, comprising: a first resistive branch extending from a first end to a second end and comprising first and second resistors connected in series; a second resistive branch extending from a first end to a second end and comprising third and fourth resistors connected in series, the second resistive branch being arranged in parallel with the first resistive branch to form a bridge circuit; a first feed wiring arrangement comprising a first trace extending from the first end of the first resistive branch to a first feed terminal for connection to a power source side; a second feed wiring arrangement comprising a second trace extending from the first end of the second resistive branch to a second feed terminal for connection to the power source side; a ground wiring arrangement connecting the second ends of the first and second resistive branches to a ground side; and a substrate on which the first and second resistive branches, the first and second traces and the first and second feed terminals are formed, the substrate comprising a portion electrically separating the first and second traces from each other.
The other objects and features of the present invention will also become understood from the following description with reference to accompanying drawings.